1. Field of the Invention
The present invention relates to a fuel supply apparatus having a fuel atomizer and, more particularly, to a fuel supply apparatus employing a fuel atomizer for an internal combustion engine in an automobile, the fuel atomizer being adapted to atomize fuel through ultrasonic vibration.
2. Description of the Prior Art
A desired objective of a fuel supply apparatus employing a fuel atomizer for an internal combustion engine for use in an automobile is its ability to atomize fuel, mix the atomized fuel with air and supply a homogeneous gaseous mixture to the engine. This objective serves to improve engine output, minimize the fuel consumption and improve the operational characteristics and performance. However, no effective means for meeting these requirements in a fuel supply apparatus having the fuel atomizer for an internal combustion engine for use in a automobile has ever been practically implemented.
The previously employed fuel atomizing techniques for an automobile, are classified into one of two techniques. According to one technique, a carburetor is used as a basic element, and a fuel from fuel discharge port is applied to a vibrator, through which fuel is ultrasonically vibrated, so as to be atomized. According to the second technique, a fuel injection system is used as a basic element, and fuel from a fuel discharge port is atomized by ultrasonic vibration.
Atomizing fuel by ultrasonic vibration is very effective in that fuel can be momentarily atomized. However installing a fuel atomizer utilizing ultrasonic vibration is very difficult. A fuel atomizer utilizing ultrasonic vibration is described for example, in Japanese Patent Publication No. 48193/1980.
According to the description in this publication, a fuel atomizer is provided in the body of a fuel supply unit. A hollow, cylindrical vibrator and an ultrasonically vibrated vibration-increasing block supporting the cylindrical vibrator are inserted respectively through a lateral bore, which is provided in the body of the fuel supply unit. The lateral bore-insertable cross-sectional area of the cylindrical vibrator is larger than that of the vibration-increasing block.
Accordingly, after the cylindrical vibrator has been set in the body of the fuel supply unit, a clearance or space exists between the inner surface of the lateral bore and the outer surface of the vibration-increasing block, in which clearance fuel is collected. The collected fuel flows along the wall surface of the body of the fuel supply unit to be supplied to the engine. This causes a decrease in the fuel atomizing effect.
After the vibration-increasing block has been inserted into the body of the fuel supply unit through the lateral bore, installation of the cylindrical vibrator to the free end of the vibration-increasing block becomes very difficult.